Support structure for preventing settlement deformation of tunnels and construction method thereof

Abstract

The invention relates to a support structure for preventing settlement deformation of tunnels and a construction method thereof. Long pipe shed method and center cross diagram method generally use constant section tunnel construction during excavation; owing to a triangular area soil body between pipe sheds and a primary support, the primary support fail to be attached to the long pipe sheds tightly, which is unfavorable for the stress of the long pipe sheds and primary support combination. The support structure comprises an annular permanent steel arch in a tunnel; the annular permanent steel arch is composed of a plurality of parallel multi-ring variable section units in the longitudinal direction of the tunnel, the longitudinal section being zigzag in shape; a temporary steel arch is arranged between sectional pilot tunnels; long pipe sheds are uniformly distributed on the top of the arch portion of the permanent steel arch; small grouting guide pipes are uniformly arranged on the outside of the two side walls of the permanent steel arch. A variable section mode is adopted in the longitudinal direction of tunnels, and the primary support can be tightly attached to the long pipe sheds; the primary support and the long pipe sheds are combined for support, thereby being capable of controlling settlement. The structure process is simple; the operation space is large; the support structure is in favor of mechanical construction and prevents the increase of construction cost.

Description

technical field [0001] The invention belongs to the technical field of tunnel support, and in particular relates to a support structure for preventing tunnel settlement deformation and a construction method thereof. Background technique [0002] When constructing tunnels in weak surrounding rocks with poor geological conditions, preventing large settlement deformation during construction is the key to design and construction. In the case of large tunnel section, shallow buried depth, strict requirements on settlement control and mechanized construction, the excavation method of long pipe shed and intersecting partition is a commonly used method. The advance support strength of the long pipe shed is high, and the divisional excavation is carried out by adopting the method of intersecting the middle partition, which can ensure that the support of each pilot tunnel is closed into a ring in time and is conducive to mechanized construction. However, due to the triangular area b...

AI Technical Summary

Problems solved by technology

However, due to the triangular area between the pipe shed and the initial support in conventionally designed equal-section tunnels, the initial support cannot be closely attached to the long pipe shed, which is unfavorable for the combined force of the long pipe shed and the initial support; in addition, the triangular area during construction The collapse of the soil due to excavation vibration requires additional shotcrete, which will lead to an increase in construction costs

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